Segmental turbine band



E mm Rm B.w R S E Feb, 24, 1925.

Filed May 9, 1921A Patented Feb. 24, 1925.

UNITED STATE nnMUNn s. n., naaivnnor NEWPORT, RHODE ISLAND.

SEGMENTAL TURBIN'E BAND.

Application filed May 9, 1921. Serial No. 468,149.

To all whom t may concern.'

.Be it known that I, EDMUND S. RBRANDT, a citizen of the United States,residing at Newport, Rhode Island, have invented new and usefulImprovements in Segmental Turbine Bands, of which the following is aspecification.

This invention relates to improvements in torpedoes and moreparticularly to improvements in the turbines used in driving thetorpedo. The invention will hereinafter be described with relation toits application to such a turbine although it is, of course, to beunderstood that the invention is applicable to turbines having otheruses.

As is well known to those skilled in the art the turbines used indriving torpedoes particularly include a disc having buckets cut throughfrom one side to theother near the periphery of the disc and thesebuckets, after being cut, are closed by means of a circumferential band,preferably made in one piece and secured to the disc by flangedoverheads of the blades between the buckets. This construction, however,has been open to some objections primarily because, due to heat and highcentrifugal speed there was a tendency for the circumferential band toeX- pand and buckle between the so-called rivets or flanged overportions causing an unbalancing of the turbine. It frequently happenedthat the band loosened at one or more points from its attaching meansand would iy outwardly due to centrifugal action and frequently wreckthe torpedo.

It is one of the primary objects of the present invention to overcomethis objection, among others, by constructing the band in a plurality ofindividual parts. In this manner each part is individually held and isso spaced 'from adjacent parts as to permit expansion and contractionwithout danger of buckling.

A further object is to provide a more reliable and efficient turbinedisc than now in use.

lVith these objects in mind attention is directed to the accompanyingsheet of drawing forming part of this disclosure and wherein similarreference characters denote corresponding` parts.

Figure l is an elevational view of the periphery of the turbine discshowing the buckets in dotted lines and overlapping' interveningsegments.

Figure 2 is a sectional view, and,

Figures 3, 4L, and 5 are ,detail views of the segments of the band.

Referring now to these drawings in detail, 1 denotes the turbine discprovided at its lperiphery with transverse curved buckets 2 indicated indotted lines in Figure l which are separated by blades 3 each providedwith a flanged head adapted to hold a `port-ion .ofv

the segmental peripheral band 5 of the disc.

These portions are generally rectangular in shape as shown in Figure 3and are pro vided with intervening overlapping edges as shown in Figures2 and 4. Thus each part is securely held by its fastening means and thespace 6 between adjacent segments permits `a certain amount ofexpansiondue to the high temperatures to which the disc is subjectedwithoutputting excessive strain on the. holding rivets et sinceexpansion of each rivet is not ,transmitted to other parts of the bandand is not cumulative asl in a continuous band. This prevents expansionstrains from increasing the strain on the rivet head t due to normalcentrifugal force so that there is no tendency of the band to strip fromthe rivet and fly'oif since the rivet is amply strong to hold againstthe centrifugal force due to a peripheral speed of 800,000 inches perminute as shown in tests.

The segments are preferably made of special band steel with two slidingfaces to permit movement due to heat of expansion and rotative expansionof the turbine wheel itself which tends to increase the peripheraldiameter thus putting a further tensile strain on a continuous bandalready weak cned by heat. This segmental part further provides forneutralizing initial riveting strains as the segments adjust themselvesunder the riveting process.

Each bucket has its own segment riveted to it instead of being made ino-ne with the bucket. Each bucket is overlapped by two segments one ofwhich is rigidly secured and the other of which slides over the head ofthe bucket when expanded by heat and under the rigidly secured segment.Each segment maintains gas tight contact with adjacent segments eventhough each segment moves with reference to adjacent segments.

It will thus be seen that the present invention provides an improvedturbine capable of high speeds without danger of stripping the band andwrecking adjacent mechanisms. j Y

lVithout further analysis, the foregoing Will so fully reveal the gistof this invention that others can by applying current knowledge readilyadapt it for various applications Without omitting certain featuresthat, from the standpoint of the prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention,and, therefore, such adaptations should and are intended to becomprehended Within the meaning and range of equivalency of thefollowing claims.

What I claim is:

l. A turbine Wheel provided with peripheral buckets and a continuousband surrounding said Wheel and closing the openings between the ends ofthe buckets, said band being formed of a plurality of independent partsin gas tight and movable contact with each other, one part for eachbucket.

Q. A turbine Wheel provided with peripheral buckets and a continuousband surrounding said Wheel and closing the opening between the ends ofthe buckets, said band being formed of a plurality of independent parts,each part comprising a rectangular piece of metal secured to a singlebucket only of the turbine ivheel and overlapping the adjacent segment.

3. A turbine Wheel provided with a plurality of peripheral buckets, aperipheral band enclosing said buckets, said band being formed of aplurality of independent segments, means for securing each segmentrigidly to one bucket only on the Wheel, such segment overlapping andunderlapping the segments at opposite sides respectively.

t. A turbine Wheel provided with a plurality of peripheral buckets, aperipheral segments on either side and sliding contact on the nextsuccessive bucket under the rigid securing of that bucket segment.

6. A turbine Wheel provided With a plurality of peripheral buckets, aperipheral continuous segmental band, said bandbeing formed of aplurality of independent segments, each segment being free to expandperipherally over and under adjoining segments Without destroying thecontinuity of the Whole band. n

Signed at Newport, Rhode Island, this 21 day of March, 1921.

E. S. R. BRANDT.

